# CVE-2026-56254: capacitor-updater - End-to-End Encryption Bypass via Private Key Distribution

> Attackers can bypass end-to-end encryption to install malicious updates on mobile devices by exploiting private key distribution flaws in the Capacitor updater plugin.

- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:H/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Jul 2026
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-j2f4-4pfc-p8rx, GHSA-v24w-qp6p-4wjw

## What is CVE-2026-56254?

CVE-2026-56254 is a high-severity vulnerability in capacitor-updater, published on 10 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In @capgo/capacitor-updater (Cap-go/capgo) before 12.128.2, the end-to-end encryption scheme distributes the private key to each device that downloads the app. Because the public key can be derived from the private key, an attacker performing a man-in-the-middle attack or compromising the Capgo server can create a validly signed update bundle and cause devices to install an update not produced by the original app maker.

Weakness: CWE-320

## Which versions are affected by CVE-2026-56254?


## How do I fix CVE-2026-56254?

No fix has been published for CVE-2026-56254 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-56254 being exploited?

There is no known exploitation of CVE-2026-56254 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-56254 and fix it if it is affected.

What it is: CVE-2026-56254 is a high-severity vulnerability in capacitor-updater, published on 10 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-56254 in the wild and no public exploit code.

Affected product: capacitor-updater. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-56254/ (Markdown: https://insights.sbomify.com/CVE-2026-56254/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-56254
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-56254
- OSV: https://osv.dev/vulnerability/CVE-2026-56254

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-56254/
Summaries are generated and may contain mistakes; the official description above is the record.